The Linux kernel verifier incorrectly interpreted the arguments for the bpf_xdp_store_bytes helper, treating a data store operation in a read‑only BPF map as a writable access. This caused legitimate BPF programs that need to write to read‑only maps to be rejected by the verifier. The patch corrects the helper prototype to match bpf_skb_store_bytes so that the verifier properly identifies the operation as a write to a permissible memory location, restoring normal functionality for these programs. No evidence is provided that the flaw could be leveraged for privilege escalation or memory corruption.

The issue exists in any Linux kernel that implements the buggy bpf_xdp_store_bytes prototype until the kernel is updated with the 2026‑45886 fix. This applies to all vendor distributions shipping the affected kernel source. Specific version ranges are not listed in the advisories; users should consult kernel changelogs that include the patch.

Because the flaw is limited to the verification of BPF helper arguments, there is no known direct exploit path or active exploitation. EPSS data are not available and the vulnerability is not listed in the CISA KEV catalog. The impact is therefore largely operational, resulting in denial of service to applications that rely on BPF programs that attempt to write to read‑only maps. The risk of exploitation is considered low based on the current public information.